Jose Mourinho and Manchester United go in search of Midas touch at Old Trafford

In accepting the challenge of attempting to drag Manchester United out of the doldrums, Jose Mourinho will also seek to restore gloss to his own tainted reputation.

The brash 53-year-old Portuguese is a serial winner, having notably won eight league titles and two Champions Leagues, but Chelsea's spectacular collapse over the first half of this season resurrected old doubts about his ability to deliver long-term success.

In accepting the challenge of attempting to drag Manchester United out of the doldrums, Jose Mourinho will also seek to restore gloss to his own tainted reputation. Getty

The season also provided recurring reminders of Mourinho's propensity for controversy and the appointment of the self-styled "Special One" is thought to have been approved despite misgivings about the potential for bad publicity at boardroom level at Old Trafford.

Discussing Mourinho's notorious eye-poke on the late Barcelona coach Tito Vilanova during his time at Real Madrid, Bobby Charlton, a United great and club director, once said: "A United manager wouldn't do that."

Louis van Gaal, Mourinho's sacked predecessor, ultimately paid the price for failing to secure Champions League qualification, but it was the pedestrian nature of the team's football that provided a lightning rod for criticism during his two-year tenure.

The European game's arch pragmatist, Mourinho is not renowned for dashing football and his poor record of promoting young players -- one area where Van Gaal enjoyed some success -- has been held against him throughout his career.

United's two greatest managers, Matt Busby and Alex Ferguson, built their success on youth and the club's fans are unlikely to react kindly if players like 18-year-old striking sensation Marcus Rashford or teenage full-backs Timothy Fosu-Mensah and Cameron Borthwick-Jackson abruptly disappear from view.

The controversy stoked by Mourinho at Stamford Bridge, meanwhile, has not yet abated, with United's new manager potentially in line to appear before an employment tribunal next month over his contentious sidelining of Chelsea medic Eva Carneiro.

Of even greater concern to the United hierarchy will be the knowledge that Mourinho's second stint at Chelsea generated unsustainable levels of friction in the changing room, with technical director Michael Emenalo citing "palpable discord" between manager and players as the chief reason for his December dismissal.

Speaking earlier this season, former AC Milan and England coach Fabio Capello asserted: "Mourinho burns out his players after a year and a half, at most two years."

- 'Siege mentality' -
But with United having finished seventh, fourth and fifth in the three seasons since Ferguson retired in 2013, desperation to return the club to title contention appears to have trumped concerns about Mourinho's ability to establish lasting foundations.

"Jose is quite simply the best manager in the game today," said United's executive vice-chairman Ed Woodward on Friday.

"He has won trophies and inspired players in countries across Europe and, of course, he knows the Premier League very well, having won three titles here.

"His track record of success is ideal to take the club forward."

And former United defender Phil Neville believes that United's fans will quickly forgive Mourinho's caustic tendencies if he brings success back to the club.

"He likes to create this siege mentality and that's what Sir Alex (Ferguson) did for 26 years," Neville told BBC Radio 5 Live.

"Sir Alex did like to create a cause for the fight, with the media and with other managers. If Mourinho does that at United, the fans will take him to their hearts."

Mourinho had rechristened himself "The Happy One" upon his return to Chelsea, but in his final months at the club he seemed to wear an almost permanent scowl.

Landing the United job, which he has long coveted, is sure to bring a smile back to his face, but frosty departures at first Real Madrid and then Chelsea mean he will not stride through the door with the same swagger that characterised his initial arrival in England from Porto in 2004.

In addition to the challenges facing him at United, his return to management serves up some tantalising clashes with rivals old and new.

At Manchester City he will cross swords again with Pep Guardiola, the former Barcelona coach, with whom he engaged in a titanic and frequently ill-tempered tussle for supremacy in Spain during his time in Madrid.

His first domestic engagement, meanwhile, will be the Community Shield against the Leicester City of Claudio Ranieri -- derided as a failure by Mourinho during their time as rival managers with Roma and Inter Milan, but who now wears England's championship crown.